Lake Butler, FloridaUnion County Information After Bradford County, Fl. was divided in 1921, Union County was created. The citizens chose the name “Union” in the hope that it would help to unify the people of the different communities. At 240 square miles, Union County is the smallest county in the area. Its principle industries are poultry, forestry, and farming. The Union County Correctional Institution is also located here.Lake Butler, Fl. was established as a town in 1859 and is the county seat. It is situated on a lake, both were named for Captain Robert Butler. Lake Butler has a population over 1,900 people and is located on about 1.7 square miles. The main employment industries in this town are education, health, and the retail trade. This is a community working together to help make Union County a better place to live. The Union County Times is the local newspaper. The postal zip code for the county is 32054 and the area code is 386.